Graphics cards in PCI-E slots 1 and 3

Is this possible to do? I'm running a GTX465 as my dedicated graphics card and I have a spare GTS250 lying around so I figured I might as well use it at a PhsyX card. However, I'd prefer not to put the GTS250 right on top of the GTX465 for obvious cooling reasons. It'd make sense to skip a PCI-E slot and put the 250 in my third slot. I did this and my system doesn't recognize the GTS250. Is this simply impossible due to the motherboard architecture? I'm on an EVGA 132-BL-E758 by the way.

Thanks

That slot might electrically be a x or a x4 slot, and not be providing enough power to the GPU. It should say in your motherboard manual.

Expansion Slots
Two PCI slots
One PCI Express x1 slot
Three PCI Express x8/x16 slots

Seems good to me.

You certainly have the physical slots for it. What motherboard is this?

I said in my original post, it's a 132-BL-E758 (EVGA x58 SLI)

Oh sorry about that. Try switching slots just to test, the motherboard supports 3way sli, no reason it shouldn't recognize a card, imo.